Screw driver



May 26, 1936, L. BALGA 2,042,376

SCREW DRIVER Filed July 19, 1935 459% @9.5,

Emea/M435 Patented May 26, '1936 PATENT OFFICE 1 Claim.

This invention relates to certain new and useful improvements in screw drivers.

The primary object of the invention is to provide a screw driver of the lside or lateral type embodying 'an elongated handle and shaft with a relatively short shaft extending at an angle to the aforesaid shaft with gear connections therebetween comprising bevel gears cut directly into the adjacent ends of the two shafts.

A further object of the invention is to-provide a screw driver of the foregoing character wherein the outer' end of the short shaft has a dovetailed cross-slot therein for the reception of a similarly shaped inner end of a screw driver blade with a tensioned locking ring slidable on the short shaft for retaining the blade in position therein.

With the above and other objects in view that will become apparent as the nature of the invention is better understood, the same consists in the novel form, combination and arrangement of parts hereinafter more fully described, shown in the accompanying drawing and claimed.

In the drawing:-

Figure 1 is a front elevational view of a screw driver constructed in accordance with the present invention;

Figure 2-is a longitudinal sectional View taken on line 2-2 of Figure 1, showingr the direct gear engagement with one shaft by a tensioned locking ring; v

i shaft end with the screw driver blade removed;

Figure 4 is a perspective View of a short screw driver blade; and v Figure 5 is a perspective View. of a relatively long screw driver blade, both blades having their 'inner ends fashioned for sliding. interlocking engagement with .the supporting shaft.

The screw driver embodies ',anlelongated casing I0 havingV an elbow formation II `at one end providing Varelativelyshort right angularlyextending casingsection I 2, the two casings I0 and I2 rotatably supporting the drive or operating. shafts for a screw driver blade.

An elongated shaft I3 is journalled in the casing section I0 and is restrained from longitudinal movement therein by the screw I4 threaded through the casing section I0 with the inner end thereof entering an annular groove I5 formed in the shaft I3. A relatively short shaft I6 is journalled in the angularly extending casing section I2 and projects therefrom as at I6a, the

' shaft I6 being restrained from longitudinal movement by means of the screw I'I threaded through the side wall of the casing section I2 and entering an annular groove I8 in the shaft I6. "Ihe adjacent ends of thel shafts I3 and I6 are intergeared as at I9` and 20 respectively 'by means vof bevel gear formations'being cut directly inV the adjacent shaft ends, this arrangement eliminating separate gear'devices.-

A hand grip 2l encloses the inner 'ends of the casing section I0 and is suitably anchored thereto, the elongated shaft I3 projecting outwardly of the casing section IIJ and hand grip 2| to accommodate the mounting thereon of an operating handle 22 that is locked thereto by means of the cross pin 23.4 It will be understood that the hand grip is engaged by one hand ofthe operator and the other hand of the operator employed for rotating the handle 22 to impart rotation to the elongated shaft I3 and to the shaft I6 by means of the .gear connections` I9 and 20 between vthe two shafts. Y

As shown more clearly in Figures 2 and 3, the outer ends of the short shaft extension I6a is ared outwardly to provide anabutment collar 24 and said shaft extension at'its outer end is provided with a transversely extending `dove tailed shaped groove 25. A relatively short-screw driver blade 26 is of wedge-shape as shown in Figures 2 and 4 and is adapted to be transversely slid into'the groove 25 when the latter lis exposed as shown in Figure 3'for interlocking engagement with the shaft extension I6a. To retain the screw driver blade 26 in position, a ring 2'I is freely mounted on the shaft extension ISa and has an annularly recessed forward side 28 that is moved into engagement-with the abutment collar 24 withv the ring closing the ends of the slot 25. A coil spring 29 surrounds the shaft extension I6a. between the outer end of the shaft section I2 and ring 21 for normally influencing the ring in a'direction of movement toward the outer end of the shaft extension and into the position shown in Figure 2. To remove the screw driver blade 26 from the shaft I6, the ring 21 is moved over the shaft extension I6a against the tension of the springy 2S to expose the ends of the cross slots 25 and at which time the screw driver blade 26rmay be easily removed from the shaft.

An elongated screw driver blade is illustrated in Figure 5 and comprises a shank 30 having a key portion 32 of wedge-shape for reception in' ytapered screw engaging end 3| with the inner end thereof reduced andv flattened to provide a the cross groove 25 in the shaft extension IGa. While the invention -has been herein referred to as a screw driver, it is to be understood that the principle of operation may be embodied in other tools, such as augers and in which blades are removably mounted. Y

From the above detailed description of the in-` vention, it is believed that the construction and operation thereof will at once be apparent and while there is herein shown and described the preferred embodiment ofthe invention, it is nevertheless to be understood that minor changes may be made therein without departing from the spirit and scope of the invention as claimed.

I claim:-

In a detachable blade mounting for screw` drivf ers, a. casing section, a shaft journalled in the casing section and projecting from one end thereof, the projecting end of the shaft having a,y transversely extending key slot in the outer end thereof, an outwardly flaring abutment shoulder at the outer terminal end of the shaft, a keyended screw driver blade removably positioned in the slot, a ring surrounding the projecting end of the shaft and having atapered inner wall for mating contact with the flaredcollar' on the shaft with the outer side ofthe ring flush with the end of the shaft at its limit of movement towards the end of the shaft, and-a coil spring surrounding the shaft and engaged with the adjacent end of the casing and ring for normally forcing the latter towards the outer end of the shaft to close opposite ends of the slot and retain the screw driver blade therein.

.f LOUIS BALGA. 

